Light signal



P e :l mw 7 f 0 w i l A 4, nL L W H 9 I L Jl J 2 b m l Hfs A'TOHNEY G.R. PFLASTERER LIGHT SIGNAL Filed Jan. 23, 1942 Patented Apr. 11, 1944LIGHT SIGNAL George R. Pflasterer, Greenville, Pa., assigner to TheUnion Switch and Signal Company, Swiss? vale, Pa., a corporation ofPennsylvania Application January 23, 1942, Serial No. 427,977

4 Claims.

My invention relates to light signals,l and it has particular referenceto light signals of the type employed in railway signal systems. Moreparticularly, my invention'relates to railway signals of the colorposition light type.

Railway signal systems are arranged ordinarily to employ one or anotherof a plurality of dilerent types of light signals, among which types areposition light and colorl position light signals. In a position lightsignal, a plurality of light projecting units each capable of propectingbeams of the same color, are arranged in rows which intersect each otherat a common point and which rows have as a common element thereof one ofthe light projecting units positioned at the point of intersection ofthe rows. 'I he unit common to the several rows is steadily energized,and by energizing the remaining units of one or another of the pluralityof rows of units, the signal is caused to display different aspectsdifferentiated from one onother` according to the position of the row ofunits caused to be energized.

Color position light signals are in genera-l similar to position lightsignals, in that a plurality of light projecting units are arranged inrows which intersect each other at a common point. This type of signaldiffers from a position light signal, however, in that although theunits forming each individual row project beams of the same color, thedifferent rows are arranged to project beams of distinctive colors. `Inaddition, the light unit employed in the position light signal at thecommon point of intersection of the rows, is not employed in the colorIposition light ,l

signal. As a result, therefore, a position light signal has an advantagein that a single light projecting unit when used in common as a portionof each of the rows, enables a relatively few units to be arranged inrows each having a relatively large number of units, usually `threeunits in number. A color position lightsignal, on the other hand, has anadvantage in that the distinctive aspects are provided not only vby theposition of the row illuminated, but also by the distinctive colorsprojected by the different rows. However, in the latter type of signalthe rows are formed of a fewer number of light units since there is nosingle unit common to all of the rows, hence in order to minimize thenumber of units required, each row is defined by a minimum number ofunits, usually by only two units.

In view of the foregoing and other important considerations, it is anobject of my present invention to provide novel and improved lightsig-l" nals incorporating all of the advantages usually `foundindividually in. .Signals of the position light and Color position.light types- Another Qbiet is i@ provide, a novel. andimproved form ofcolor position light signal.

An additional object 'is to provide a railway signal of the colorposition light type, arranged to employ a single light unit as a portionof each of the rows of units, and which single unit is arranged toproject a beam of light having one or another of a plurality of colorsone corresponding to` Ieach of the distinctive colors projected by theseveral rows.

A further object is to provide novel and improved forms of light signalsof the type em- V ployed in railway signal systems.

In practicing my invention, the above-mentioned and other importantobjects and characteristic features which will become readily apparentfrom the following description, are attained by providing a lightprojecting unit at the common point of intersection of the rows of lightunits of a color position light signal. This additional light unit isprovided with means for causing the unit to Aproject a beam of lighthaving one or another of a plurality of colors corresponding one to eachof the distinctive colors projected by the rows of units.

I shall describe two forms of signals embodying my invention, and shallthen point out the novel features thereof in claims.

In the accompanying drawing, Fig. 1 is a diagrammatic view representingone from of a color position light signal embodying my invention. Fig, 2is a diagrammatic view representing a modification of the signalillustrated in Fig. 1, and also embodying my invention. Similarreference characters have been employed in the two views to designatecorresponding parts.

According to. the invention, an improved railway signal of the colorposition light type is provided by incorporating into the usual type ofsuch a signal a light projecting unit disposed at the point ofintersection of the rows of light emissive or projecting units. By usualtype of color position light signal is meant the well-known type ofsignal heretofore proposed and now i-n use in certain of the railwaysystems. This type of signal is relatively simple, and comprises aplurality of light emissive or projecting units arranged to projectbeams of light in parallel relation and in the same direction, and whichunits are arranged in rows which intersect each othe rat a commonpoint.` rIhis point of intersection may be intermediate the ends oi therowsl (see Fig. 1 of the accompanying drawing) I or it may be at one endof the rows see Fig. 2).

In either case, itV has been customary to leave blankA the point ofintersection, that is, a light unit is not placed at that point. Eachrow of units is, therefore,` usually defined by two units, as forexample the rows of units of the usual type of eolol position lightsignal would be dened by the units at the ends of the rows representedin Fig. l, or by the two adjoining units projected.

on the outer ends of the rows as represented in Fig. 2, the inner endsof the rows of this signal being considered as intersecting.

The usual type of lcolor position light signal ordinarily consists alsoof a circular field (see Fig. 1) or sector shaped background 5a (seeFig. 2) provided with apertures or openings 6 'in which are mountedcover glasses (usually clear or colorless) and in back of which aremounted light emissive or projecting units. The openings in the eld areusually so located that a vertical, a horizontal, and at least onediagonal (45) row of units are provided. The signal itself is usuallysupported on a mast 8 to which it is suitably secured and the mast 8 inturn is secured as desired to a signal bridge, cantilever post, orconcrete b ase 9.

The light projecting units employed in the usual type of color positionlight signal are of well-known construction, not illustrated in the:drawing, and it is deemed sufficient for the present description tostate that each unit usually comprises a lamp case in which are mount-.,ed a reflector, a light source and a color filter or screen. The colorfilters or screens mounted in the units of any one row are of the samecolor, but the lters of the different rows are of distinctive colors.tomary to employ green color lters in the units Thus, for example, it iscusof the vertical row, yellow color filters in the units of thediagonal row, and red color filters in the units of the horizontal row,whereby vwhen the units `of the vertical row are energized, a verticalrow of green beams of light is projected; when the diagonal row of unitsis -energized a diagonal row of yellow beams is projected; and when thehorizontal row of units is energized, a horizontal row of red beams isIt is therefore apparent that this type of signal displays distinctiveaspects difierentiated from one another not only by the position of therow oi' units energized but also -by the color of the beams projected bysuch rows. ,jected bythe several rows of units are indicated by placingthe reference characters G, Y and R in the openings B of the fieldthrough In the drawing, the different colors prowhich are projectedgreen, yellow and red beams, respectively.

As mentioned heretofore, the improved signal 'embodying my inventioncomprises a color position light signal of the usual type having an.additional light projecting unit at the point of intersection of theseveral rows of units, and

-which additional unit is provided with means for causing the unit toproject a beam of light having one or another of a plurality of colorsone for eachY of they distinctive colors projected by -the rows oi unitsof the signal. Asignal therefore requires an aperture 6 to be providedin the signal field 5 at the point of in- The improved tersection of therows of units, a cover glass mounted in such aperture, and a lightproject- .ing unitcapable of projecting a beam of light having one oranother of a plurality of colors. Such a unit is designated in thedrawing by the reference character SM and is representeddiagrammatically as comprising a searchlight type of signal mechanismhaving a rotor or vane Ill to which are afxed a plurality ofdistinctively colored lters or roundels designated by the referxencecharacters VG, R and Y to indicate that "suchvillters are colored green,red and yellow, respectively. Unit SM also comprises a light :source(not shown) together with a suitable optical system by means of whichlight from the source is projected through the one of the color lterspositioned in the operative position of the signal, that is, in theposition of alignment with the cover glass mounted in the associatedopening 6 provided in the signal field. In the particular form of signalmechanism illustrated, rotor IIJ is biased to a center or mid position,wherein the red roundel R is positioned in the operative position of thesignal, and is caused to rotate to one extreme position or the otheraccording as an operating winding II is energized by current of onerelative polarity or the other. When rotor I0 is caused to rotate to itsright-hand extreme position, as viewed in the drawing, roundel G- ispositioned in the operative position of the signal, whereas when rotorI0 is caused to rotate to its other or lefthand extreme position,roundel VY is moved into the operative position of the signal. Signalmechanisms of the type described are well known in the art, and may, forexample, be of the type shown and described in detail in Letters Patentof the United States, No. 1,864,224, granted to Wesley B. Wells on June21, 1932. Other types of searchlight signal mechanisms may, of course,be employed, as for example the type wherein the yellow lter Y isinterposed between the red R and green G filters.

The winding II of unit SM may be supplied with current of one relativepolarity or the other over circuit means not forming a part of thepresent invention and of a type well known in .the art. However, toindicate the manner of control of the signal mechanism, a representativecircuit arrangement is illustrated in the drawing as comprising acircuit extending from one terminal B of a suitable source ofunidirectional current, such as a battery not shown butl having itsopposite terminals designated by the reference characters B and C,through front contact I4 of a control relay RI, front contact I5 ofanother control relay R2, the winding II .of signal lmechanism SM, andfront contact I6 cause roundel R to be positioned in the operativeposition of the signal.

The relays RI and R2 may be controlled in any suitable manner not shown.It should, however, be pointed out that it is contemplated to interlockthe control of the relays with the control of the other light units ofthe signal in such manner that when relay RI is released and the commonunit SM is conditioned to project a red beam, the other two units of thehorizontal row are likewise conditioned to project their respective redbeams; when relay RI is picked up 65 to project a yellow beam, the othertwo units of and relay R2 is released to condition unit SM the diagonalrow are Asimilarly conditioned to project their yellow beams; and whenboth relays RI and R2 are picked up to condition unit SM to project itsgreen beam,y the remaining units of the vertical row are conditioned toproject their green beams. This control of the other light units of thesignal may be eiected in Yany suitable manner, as by controlling thelight units over contacts of relays RI and R2. For

example, the light source of unit SM may be constantly energized, thuscausing the unit to project a beam of light having a color determined bythe particular color filter positioned intermediate such source and theassociated cover glass mounted in the aperture of eld 5. When relay RIis released, roundel R of unit SM is interposed in the path of lightemitted from the source and the unit accordingly is caused to project ared beam. At this time, the other units of the horizontal row may beenergized over an obvious circuit including a suitable source ofcurrent, the light sources of the other units of such row, and backcontact i1 of relay RI, whereby the signal will be caused to projectthree red beams aligned horizontally. When relay Rl is picked up, andrelay R2 is released to cause yellow roundel Y of unit SM to beinterposed in the path of light projected from the unit, the other unitsof the diagonal row may be energized over an obvious circuit whichincludes a suitable source of current, the light sources` of such unitsof the diagonal row, front contact l1 of relay RI and back contact I8 ofrelay R2, whereupon the signal will project three yellow beams aligneddiagonally. If relays Rl and R2 are both picked up, then unit SM iscaused to position green roundel G in the path of its beam of light, andthe other units of the vertical row may be energized over an obviouscircuit including the suitable source of current, the light sources ofthe other units of the vertical row, front contact I1 of relay RI andfront contactl I8 of relay R2, whereupon the signal will project threegreen beams aligned vertically.

It is, of course, to be understood that the above described manner ofcontrol of the light units of a signal embodying my invention is merelyillustrative, and other arrangements may be employed for causing thesignal to display distinctive aspects. For example, approach control ofthe energization of the various units may be employed, whereby thesignal is caused to be normally dark and is caused to project a lightedaspect only upon the approach of a train to the signal. Also, the commonunit SM and the other units of the signal may be controlled in suchmanner as to cause the common unit to project a beam of light which mayor may not be of the same color as the beams projected by the otherunits of the row energized. Thus, two Vertical green beams may beprojected with the third beam having a green, yellow or red color; twodiagonal yellow beams may be projected with a third beam of green,yellow or red color; and two horizontal red beams may be projected witha. third beam of green, yellow or red color. In any event, the aspectprovided by the signal constitutes a plurality of beams projected byunits Varranged in rows and having a unit common to each of the rows,and which aspects are differentiated from each other by the position ofthe beams projected and by the color of such projected beams. Itfollows, therefore, that a signal constructed in accordance with myinvention incorporates all of the advantages heretofore foundindividually in the position light and color position light type ofsignals.

Although I have herein shown and described only two forms of signalsembodying my invention, it is understood that various changes andmodications may be made therein within the scope of the appended claimswithout defparting from the spirit and scope of my invention.

Having described my invention, what I claim is:

1. In a color position light signal wherein a plurality of lightprojecting units are arranged in rows for providing distinctive aspectsaccording to the particular row and color of the beams projected, theunits of each row projecting beams of the same color and the diiferentrows projecting beams of distinctive colors, a light projecting unitcommon to all of said rows, and a plurality of color lters onecorresponding to each of said distinctive colors for selectiveinterposition in the beam projected from said common light projectingunit for causing such unit to project a beam of light having one oranother of a plurality of colors one corresponding to each of saiddistinctive colors.

2. A light signal comprising a plurality of light projecting unitsarranged in a plurality of rows intersecting each other at a commonpoint, one of said plurality of light units at said common point forminga portion of each of said rows, the beams projected by said units beingin parallel relation and in the same direction, a plurality ofdistinctively colored filters one for each of said rows provided forsaid common light unit for se.- lective interposition in the beam ofsuch unit, and a plurality of color filters one disposed in the beamprojected from each of the remaining light units, the filters of theremaining light units of each row being of uniform color and the filtersof the different rows being of a different one of said distinctivecolors.

3. In combination with a plurality 0f light units arranged in rowsintersecting at a common point provided with one of said light unitscommon to all of said rows, a plurality of distinctively colored ltersone for each of said rows, a mechanism for selectively interposing oneor another of said light filters in the beam of said common light unit,and a plurality of color lters one disposed in the beam of each of theremaining light units, the lters of the remaining light units of eachrow being of uniform color and the filters of the different rows beingof a different one of said distinctive colors.

4. A light signal comprising a plurality of light units arranged in aplurality of rows intersecting each other at a common point, one of saidplurality of light units at said common point forming a portion of eachof said rows, the beams projected by said light units being in parallelrelation and in the same direction, a plurality of distinctively coloredlters one for each of said rows, a mechanism for selectively interposingone or another of said light filters in the beam of said common lightunit, a plurality of color filters one disposed in the beam of each ofthe remaining light units, the lters of the remaining light units ofeach row being of uniform color and the lters of the different rowsbeing of a different one of said distinctive colors, means forconstantly energizing said common light unit, and means for selectivelyenergizing the remaining light units of one or another of said rows andsimultaneously controlling said mechanism to interpose in the beam ofsaid common unit the particular iilter having the color corresponding tothe color of the lters of the remaining light units of the row selectedto be energized.

GEORGE R. PFLASTERER.

